Spiral Resonators Array in inductive Wireless Power Transfer Applications: An Equivalent Lumped Circuit Retrieval Method

In this paper we introduce a retrieval method to derive an equivalent lumped circuital model for spiral resonators arrays in inductive Wireless Power Transfer applications. We first introduce the theoretical concepts at the basis of the array description through an equivalent RLC circuit. Then, we develop a numerical test-case to evaluate the performance of the proposed method, constituted by resonant driving and receiving coils with an interposed spiral resonators array; finally, we compare full-wave simulations and analytical estimations. The observed excellent agreement between full-wave and analytically-retrieved impedance parameters demonstrates the efficiency of our procedure, encouraging further analysis.